The brown howler (Alouatta guariba), also known as brown howler monkey, is a species of howler monkey, a type of New World monkey that lives in forests in southeastern Brazil and far northeastern Argentina (Misiones). It lives in groups of two to 11 individuals. Despite the name "brown howler", it is notably variable in colour, with some individuals appearing largely reddish-orange or black. The two subspecies are: \n* Northern brown howler (A. g. guariba), listed as critically endangered \n* Southern brown howler (A. g. clamitans)